1. Field of the invention
The invention relates to a foot-propelled wheeled hobby and/or sport device.
2. Description of the Related Art
Popular devices for spending one's spare time doing exercise are various foot-propelled structures rolling on wheels, and the most popular one of these, which has been used all over the world for several decades, is the traditional bicycle propelled with foot-pedals while sitting on a saddle. Beside bicycles, which have a relatively complicated structure and large size, numerous other simpler and smaller foot-propelled wheeled hobby devices are also known which are used for sport-like hobby activities, such as roller-skates, which are attached to the user's feet, or two-wheeled scooters, which also have handlebars similar to bicycle handlebars and a long, narrow board to the front and to the rear part of which the wheels are attached, and the user stands with one foot on the board while propelling the scooter with the other foot. Another widely used device is the skateboard, which has four wheels with a small diameter, the user stands on it and propels it with movements similar to propelling a scooter, and on a sloping surface the user stands on it with both feet and rolls on it balancing with his/her body. Finally we mention a known foot-propelled sport or hobby device which has one single wheel with spokes similar to bicycle wheels, but for the use of this device individual—balancing—skills are needed which not many people have, so it could not become a wide-spread article used by masses of people, even in its form stabilised with servomotors, which obviously increases production costs significantly.
In connection with skateboards mentioned above it must be pointed out that—although they are fairly popular hobby devices—they are rather slow and not very manoeuvrable due to rather high resistance of the four small diameter wheels. Also skateboards can also be criticised from the aspects of safety, because if the user falls off this sport device or steps off for some other reason, the device escapes, for example, on a sloping road it may roll down and cause an accident.
International patent application No. PCT/HU2003/000043, published on 31st Dec. 2003 under No. WO 2004/000635 A1 describes a foot-propelled wheeled hobby and/or sport device which has foot-boards and a wheel situated between two side-plates, which side-plates are suspended on the axle of the wheel; foot-boards situated under the axle of the wheel, protruding outwards are connected to the side-plates; and during the appropriate use of the device the side-plates project over the knees of the user standing on one or both of the foot-boards, ensuring a supporting surface for the knees (a).
This device makes propelling and movement possible similar to using a skateboard. The user of the device stands on the foot-board with one foot putting eccentric loading on the device by this, and with the other foot he/she propels the device pushing away from the ground, and progresses by repeating these actions with alternate feet, that is standing on the foot-board and pushing away from the ground alternately on the two sides. Composite action between the wheel and the user's foot standing on the foot-board putting eccentric loading on the device is ensured by the friction force generated between the knees—partly the lower part of the leg—and one of the side-plates from the horizontal reaction force of the torque generated by the eccentric loading in the course of the alternate actions of standing and pushing.
Although this device is faster and more manoeuvrable than a skateboard, there is a risk of tilting forwards or backwards especially in the case of high travelling speeds that can be reached by intensive propelling, which requires fairly good skills from the user. A further problem may be that the supporting—friction connection—of the lower part of the leg and the knee against the side-plate represents a significant loading on the user's knee.